Axial-flow steam-turbine



K. BAUMANN. AXIAL FLOW ST EAM TURBINE. APPLICATION FILED JULY 5, 1919-- &

INVENTOR I a a s K. BAUMANN.

AXIAL FLOW STEAM TURBINE.

APPLICATION FILED JULY 15. 1919.

Patented Aug. 9,1921

3 SHEETS-SHEET 3 INVENTOR ,f)

UNITED STATES ATENT--oF Iica KARL BAUMANN, OF URMSTON, ENGLAND, ASSIGNORTO THE BRITISH WESTING- HOUSE ELECTRIC AN D MANUFACTURING COMPANY LIMITED, A: COMPANY OF GREAT BRITAIN.

Application filed July 15,

To all whom it may concern:

Be it known that I, KARL 'BAUMANN, a

citizen of the Confederation of Switzerland,

hau'st, and has for its object torprovide "animproved construction of turbine of this kind such that the divided portions of steam passing through said separate sections of.

blading flow in substantially the same axial direction to the exhaust.

' According to the invention one portion of g the steam leaving the moving blades of an intermediate stage"of the turbine flows through a section of blading comprising one or more rows of stationary and moving blades and thence to the exhaust, while another portion flows through passages con trived in the disk, shaft or drum on which the rows of moving blades of the above mentioned section of blading are'mounted, and

thence through one or more further sections of blading each comprising one or more rows of stationary and moving blades to the exhaust, said further section or sections of blading being located farther, along "the shaft or drum of the turbine in the dire-ction of steam flow thansaid first mentioned section. In the accompanying drawings Figure .1 is a central, vertical, longitudinal section of the low pressure portion of a steam turbine constructed in accordance with this'invenT tion, Fig. 2 being a cross-sectional View n; the' line 11-11 of Fig. 1.' Fig. 3 is a, View similar to Fig. 1 andFi' .,45 a cross-sectional viewbn the line 1VI of Fig. 3 'illustrating a modified constructi n; Fig. '5 is also" a view similar to'F-ig. 1' and Fi 6 a; crosssec'tional view on. the line VI- I of Flg. 5" showing another' constructional -modification. Likereaeencenumerns are" utilized throughout the'i several, figures to indicate similar parts:-

AXIAL-FLOWSTEAM-TURBINE. V i

Specification of Letters Patent. Paltlltd 1919. ser al No. 310,995.

Referring first to Figs. 1 and 2, the tur-' bine cylinder is indicated at 7 and the tur--' bine shaft at 8, the exhaust casing at 9 and the exhaust outlet from the turbineat 10.;

The steam-leaving the moving blades 'llof an intermediate stage is divided by a circumferential wall 12 formed in a diaphragm 18'secure d ,in' position in the turbine cylinder 7 into two annular portions 'an inner and an outer portion; The outer portion of steam flows through the diaphragm 13' out-f side; the circumferential wall 12, throughfa 860131011 of blading comprising alternating rows of stationary and moving blades'indi-j cated respectively at'14c, 15, 16, 17 an'di18," and thence to the" exhaust. Them-wing;

blades 14, 16 and 18 are mounted in a ring 19'shrunk on to the ends of a pluralityof arms 20, 20 extendingradially" from the so a shaft 8.- The spaces incl'o'sed between the arms 20, and'the ring 19 shrunk on to their ends form a series of passages. 21,21

through which the, inner"portionfoffsteamj i" flowing through the diaphragm '13] within" the circumferential wall 12 passes to another c o Of a g located fartherfalon the shaft comprising rows of stationary [and moving blades respectively indicated'at 22,, 1 23, 24:, 25, 26'and'27 andthenceito the e x-v I haust. The stationary blades 22,24 and 26f.

of {this section of are J mounted in a funnel-shaped diaphragm 28. secured in position from longitudinal ribs 29 formed in the exhaust casing of the turbinefi Said funnel-shaped diaphragm'f28 1 extends into close proximity with the ring 19, 1and forms a guide for fthe' steam fl' eaving theqrow of moving blades 18 and flowingIintofthefex haust and also "a passage for the steam v leaving. the passages 21, 21 and flowing to" the section of blading 22, 23-, etc. The rowsof movingfbl ades 23 25 'aHdQQ'T ai' e mounted; (I or bl'ade iholderf in the periphery of a, 'disl 30 shrunk' on' the shaft Asillustrated in Fig. 1

, a the; s tio ary guide blades for the outer p0r'ti on' of"steani between the rows of moving blades 11 14 are-formed in the diaphragmjlg .angliif although this is a convenient construction to. ept: the, di phr gm; 1.3' f ay b L 6 on-i.

structedlas merely to support the" circumfer enti'a'l walli 12- iir po sitionfaflro w ofstationed in the turbine cylinder in front of the moving blades 1 1 Similarly to the rows of stationary guide blades 15 and 17.

The diaphragm 13 is preferably provided with an inner circumferential wall 31 to guide the inner annular portion of steam leaving the row of moving blades 11 toward the passages 21. The vanes, webs, or the like 31 which serve to support the circumferential wall 31 from the wall 12 may with. advantage be so formed as to deflect the inner annular portion of steam leaving the row of moving blades 11 so that it will enter the passages 21 with a minimum of shock.

It will be observed that with the construction described above and illustrated in Figs. 1 and 2, both portions into which the steam leaving the row of moving blades 11 is divided flow in parallel in the same axial direction through. the sections of blading 14 to 18 and 22 to 27 respectively, before reaching the exhaust.

The construction illustrated in Figs. 3 and 4 is, in many respects, similar to that described above with reference to Figs. 1 {LIIC 2. In this form of the invention however, the passages 21 for the inner annular portion of steam are milled out of the solid shaft or rotor 8 as indicated and are extended in axial length so that at their ends they approach those portions of the shaft on which the rows of moving blades 11 and 23 are mounted. With this form the inner circumferential guide wall 31 shown in Fig. 1 is omitted, the longitudinally curved shape of the base of the recesses forming the passages 21 as shown in Fig. 3,. in conjunction with the circumferential wall 12 serving to gulde the inner annular portion of steam leaving the row of moving blades" 11 into the passages below the ring 19. The construction illustrated in Figs. 3 and 4 enables the turbine to be built with a more rigid shaftbut otherwise the construction is very similar to that shown in Figs. 1 and 2. In

either form the passages 21 may run parallel with the turbine axis or take a spiral v or helical direction with reference thereto.

Figs. 5 and 6 illustrate the invention applied to a turbine in which the rows of movmg blades are mounted on a hollow drum 32. The drum is provided with a plurality of slots or openings 33 through which the inner annular portion of steam leaving the row of moving blades 11 enters the interior of the drum 32. Two series of circumferentially arranged apertures 34, 35, respec-, tively perm t the steam which. has entered: the drum to pass out again and flow through two further sections of stationary and mov- 'ing blades, respectively indicated at 22, 23,,

24, 25, 26, 27, and 22 23 24a, 25 26, 27

With the construction illustrated in F igsf 5 and 6 it will be seen that the steamleaving the row of movingblades 11 is subdivided into portions which flow in parallel and in the same axial direction to the ex haust through three independent sections of blading located at different points along the shaft in the direction of the flow of steam through the turbine.

Tt'is to be understood that the invention is" not limited to the constructional forms herein described and illustrated which have been given byway of example only as various changes and modifications may be made therein without departing from the spirit and scope of the invention.

1 claim as my invention:

1. A steam turbine of the axial, flow type in whichthe steam leaving the moving blades of an intermediate stage is divided, one portion thereof flowing through a section of blading comprising one or more rows of stationary and moving blades and thence to the exhaust and another portion flowing throughpassages contrived in the rotor on which the rows of moving blades of the aforesaid section of blading are mounted and thence through one or more further sections of blading each comprising one or more rows of stationary and moving blades to the exhaust, said further sectionor sections of blading being located farther along. the rotor in the direction of the flow of steam through the turbine than said first mentioned section of blading so that the several portions of steam leaving said intermediate stagewill" How in parallel in the same axialdirection through allof said sections of blading.

2. In a steam turbine of the axial flow type having a casing on which stationary blades are mounted and a rotary drum on which moving bladesare mounted and in which. the steam flows in the Same axial direction through all sections ofblading, means for dividing the steam leaving the moving blades of an 'intermediatesection, means for passing-one portion of the? steam through a low pressure section comprising one or more rows of stationary and moving blades and thenceto exhaust, and means for passing another portion of the steam through the rotary drum to a succeeding low pressure section comprising one or, more rows of stationary and moving blades and thence to exhaust. e

V3. in an axial flowv turbine,.the combina tion with two low pressure sections through which steam passes in parallel in the same axial direction, having, a casing on which are mounted stationary blades and. a rotor on which are mounted themovingblades of the sections, of means for passing steam through the rotor to one of said low pressure sections.

4;. In an axial flow turbine, the combination with twolow pressure sections through which steam passes in parallel in the same axial direction, a casing on which are mount-f ed stationary blades and a rotor on which are mounted the moving blades of the sections, of means for directing the flow of steam through the rotor past one section and to the other section.

5. In combination with an axial flow turbine comprising two low pressure sections through which steam flows in parallel in the same axial direction, a casing on which the stationary blades and a rotor on which the moving blades of the sections are mounted, means for passing steam directly to the section located first in the direction of travel of the steam and means for passing steam through the rotor to the-other section.

6. In a turbine, the combination of a casing, arotor, a section including blading carried by the casing and rotor, a plurality of successive low-pressure sections each including similarly arranged blading carried by the casing and rotor and receiving steam dis-- charged from the first-named section and discharging it in the same general axial direction, and means in the rotor for by-passing a. portion of the steam discharged from the first-named section around the first lowpressure section and for supplying said steam to the other section or sections.

7. In a turb1ne,'the comblnation of a casing, a rotor, a section carried by the casing supplying such portion to the other section or Sections, and guide means between the low-pressure sections to guide the exhaust of a, low-pressure section around a succeeding low-pressure section and to guide said by- 3 passed steam to the latter. a In testimony whereof I have hereunto subscribed my name this tenth day of June,1919.

KARL BAUMANN. 

